text: /*-
   * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
   * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
   * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * a) Redistributions of source code must retain the above copyright notice,
   *   this list of conditions and the following disclaimer.
   *
   * b) Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *   the documentation and/or other materials provided with the distribution.
   *
   * c) Neither the name of Cisco Systems, Inc. nor the names of its
   *    contributors may be used to endorse or promote products derived
   *    from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
   * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
   * THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include <sys/cdefs.h>
  __FBSDID("$FreeBSD$");
  
  #ifndef _NETINET_SCTP_LOCK_BSD_H_
  #define _NETINET_SCTP_LOCK_BSD_H_
  
  /*
   * General locking concepts: The goal of our locking is to of course provide
   * consistency and yet minimize overhead. We will attempt to use
   * non-recursive locks which are supposed to be quite inexpensive. Now in
   * order to do this the goal is that most functions are not aware of locking.
   * Once we have a TCB we lock it and unlock when we are through. This means
   * that the TCB lock is kind-of a "global" lock when working on an
   * association. Caution must be used when asserting a TCB_LOCK since if we
   * recurse we deadlock.
   *
   * Most other locks (INP and INFO) attempt to localize the locking i.e. we try
   * to contain the lock and unlock within the function that needs to lock it.
   * This sometimes mean we do extra locks and unlocks and lose a bit of
   * efficency, but if the performance statements about non-recursive locks are
   * true this should not be a problem.  One issue that arises with this only
   * lock when needed is that if an implicit association setup is done we have
   * a problem. If at the time I lookup an association I have NULL in the tcb
   * return, by the time I call to create the association some other processor
   * could have created it. This is what the CREATE lock on the endpoint.
   * Places where we will be implicitly creating the association OR just
   * creating an association (the connect call) will assert the CREATE_INP
   * lock. This will assure us that during all the lookup of INP and INFO if
   * another creator is also locking/looking up we can gate the two to
   * synchronize. So the CREATE_INP lock is also another one we must use
   * extreme caution in locking to make sure we don't hit a re-entrancy issue.
   *
   * For non FreeBSD 5.x we provide a bunch of EMPTY lock macros so we can
   * blatantly put locks everywhere and they reduce to nothing on
   * NetBSD/OpenBSD and FreeBSD 4.x
   *
   */
  
  /*
   * When working with the global SCTP lists we lock and unlock the INP_INFO
   * lock. So when we go to lookup an association we will want to do a
   * SCTP_INP_INFO_RLOCK() and then when we want to add a new association to
   * the SCTP_BASE_INFO() list's we will do a SCTP_INP_INFO_WLOCK().
   */
  
  extern struct sctp_foo_stuff sctp_logoff[];
  extern int sctp_logoff_stuff;
  
  #define SCTP_IPI_COUNT_INIT()
  
  #define SCTP_STATLOG_INIT_LOCK()
  #define SCTP_STATLOG_LOCK()
  #define SCTP_STATLOG_UNLOCK()
  #define SCTP_STATLOG_DESTROY()
  
  #define SCTP_INP_INFO_LOCK_DESTROY() do { \
          if(rw_wowned(&SCTP_BASE_INFO(ipi_ep_mtx))) { \
               rw_wunlock(&SCTP_BASE_INFO(ipi_ep_mtx)); \
          } \
          rw_destroy(&SCTP_BASE_INFO(ipi_ep_mtx)); \
        }  while (0)
  
  #define SCTP_INP_INFO_LOCK_INIT() \
          rw_init(&SCTP_BASE_INFO(ipi_ep_mtx), "sctp-info");
  
  
  #define SCTP_INP_INFO_RLOCK()	do { 					\
               rw_rlock(&SCTP_BASE_INFO(ipi_ep_mtx));                         \
  } while (0)
  
  #define SCTP_MCORE_QLOCK_INIT(cpstr) do { \
  		mtx_init(&(cpstr)->que_mtx,	      \
  			 "sctp-mcore_queue","queue_lock",	\
  			 MTX_DEF|MTX_DUPOK);		\
  } while (0)
  
  #define SCTP_MCORE_QLOCK(cpstr)  do { \
  		mtx_lock(&(cpstr)->que_mtx);	\
  } while (0)
  
  #define SCTP_MCORE_QUNLOCK(cpstr)  do { \
  		mtx_unlock(&(cpstr)->que_mtx);	\
  } while (0)
  
  #define SCTP_MCORE_QDESTROY(cpstr)  do { \
  	if(mtx_owned(&(cpstr)->core_mtx)) {	\
  		mtx_unlock(&(cpstr)->que_mtx);	\
          } \
  	mtx_destroy(&(cpstr)->que_mtx);	\
  } while (0)
  
  
  #define SCTP_MCORE_LOCK_INIT(cpstr) do { \
  		mtx_init(&(cpstr)->core_mtx,	      \
  			 "sctp-cpulck","cpu_proc_lock",	\
  			 MTX_DEF|MTX_DUPOK);		\
  } while (0)
  
  #define SCTP_MCORE_LOCK(cpstr)  do { \
  		mtx_lock(&(cpstr)->core_mtx);	\
  } while (0)
  
  #define SCTP_MCORE_UNLOCK(cpstr)  do { \
  		mtx_unlock(&(cpstr)->core_mtx);	\
  } while (0)
  
  #define SCTP_MCORE_DESTROY(cpstr)  do { \
  	if(mtx_owned(&(cpstr)->core_mtx)) {	\
  		mtx_unlock(&(cpstr)->core_mtx);	\
          } \
  	mtx_destroy(&(cpstr)->core_mtx);	\
  } while (0)
  
  #define SCTP_INP_INFO_WLOCK()	do { 					\
              rw_wlock(&SCTP_BASE_INFO(ipi_ep_mtx));                         \
  } while (0)
  
  
  #define SCTP_INP_INFO_RUNLOCK()		rw_runlock(&SCTP_BASE_INFO(ipi_ep_mtx))
  #define SCTP_INP_INFO_WUNLOCK()		rw_wunlock(&SCTP_BASE_INFO(ipi_ep_mtx))
  
  
  #define SCTP_IPI_ADDR_INIT()								\
          rw_init(&SCTP_BASE_INFO(ipi_addr_mtx), "sctp-addr")
  #define SCTP_IPI_ADDR_DESTROY() do  { \
          if(rw_wowned(&SCTP_BASE_INFO(ipi_addr_mtx))) { \
               rw_wunlock(&SCTP_BASE_INFO(ipi_addr_mtx)); \
          } \
  	rw_destroy(&SCTP_BASE_INFO(ipi_addr_mtx)); \
        }  while (0)
  #define SCTP_IPI_ADDR_RLOCK()	do { 					\
               rw_rlock(&SCTP_BASE_INFO(ipi_addr_mtx));                         \
  } while (0)
  #define SCTP_IPI_ADDR_WLOCK()	do { 					\
               rw_wlock(&SCTP_BASE_INFO(ipi_addr_mtx));                         \
  } while (0)
  
  #define SCTP_IPI_ADDR_RUNLOCK()		rw_runlock(&SCTP_BASE_INFO(ipi_addr_mtx))
  #define SCTP_IPI_ADDR_WUNLOCK()		rw_wunlock(&SCTP_BASE_INFO(ipi_addr_mtx))
  
  
  #define SCTP_IPI_ITERATOR_WQ_INIT() \
          mtx_init(&sctp_it_ctl.ipi_iterator_wq_mtx, "sctp-it-wq", "sctp_it_wq", MTX_DEF)
  
  #define SCTP_IPI_ITERATOR_WQ_DESTROY() \
  	mtx_destroy(&sctp_it_ctl.ipi_iterator_wq_mtx)
  
  #define SCTP_IPI_ITERATOR_WQ_LOCK()	do { 					\
               mtx_lock(&sctp_it_ctl.ipi_iterator_wq_mtx);                \
  } while (0)
  
  #define SCTP_IPI_ITERATOR_WQ_UNLOCK()		mtx_unlock(&sctp_it_ctl.ipi_iterator_wq_mtx)
  
  
  #define SCTP_IP_PKTLOG_INIT() \
          mtx_init(&SCTP_BASE_INFO(ipi_pktlog_mtx), "sctp-pktlog", "packetlog", MTX_DEF)
  
  
  #define SCTP_IP_PKTLOG_LOCK()	do { 			\
               mtx_lock(&SCTP_BASE_INFO(ipi_pktlog_mtx));     \
  } while (0)
  
  #define SCTP_IP_PKTLOG_UNLOCK()	mtx_unlock(&SCTP_BASE_INFO(ipi_pktlog_mtx))
  
  #define SCTP_IP_PKTLOG_DESTROY() \
  	mtx_destroy(&SCTP_BASE_INFO(ipi_pktlog_mtx))
  
  
  
  
  
  /*
   * The INP locks we will use for locking an SCTP endpoint, so for example if
   * we want to change something at the endpoint level for example random_store
   * or cookie secrets we lock the INP level.
   */
  
  #define SCTP_INP_READ_INIT(_inp) \
  	mtx_init(&(_inp)->inp_rdata_mtx, "sctp-read", "inpr", MTX_DEF | MTX_DUPOK)
  
  #define SCTP_INP_READ_DESTROY(_inp) \
  	mtx_destroy(&(_inp)->inp_rdata_mtx)
  
  #define SCTP_INP_READ_LOCK(_inp)	do { \
          mtx_lock(&(_inp)->inp_rdata_mtx);    \
  } while (0)
  
  
  #define SCTP_INP_READ_UNLOCK(_inp) mtx_unlock(&(_inp)->inp_rdata_mtx)
  
  
  #define SCTP_INP_LOCK_INIT(_inp) \
  	mtx_init(&(_inp)->inp_mtx, "sctp-inp", "inp", MTX_DEF | MTX_DUPOK)
  #define SCTP_ASOC_CREATE_LOCK_INIT(_inp) \
  	mtx_init(&(_inp)->inp_create_mtx, "sctp-create", "inp_create", \
  		 MTX_DEF | MTX_DUPOK)
  
  #define SCTP_INP_LOCK_DESTROY(_inp) \
  	mtx_destroy(&(_inp)->inp_mtx)
  
  #define SCTP_INP_LOCK_CONTENDED(_inp) ((_inp)->inp_mtx.mtx_lock & MTX_CONTESTED)
  
  #define SCTP_INP_READ_CONTENDED(_inp) ((_inp)->inp_rdata_mtx.mtx_lock & MTX_CONTESTED)
  
  #define SCTP_ASOC_CREATE_LOCK_CONTENDED(_inp) ((_inp)->inp_create_mtx.mtx_lock & MTX_CONTESTED)
  
  
  #define SCTP_ASOC_CREATE_LOCK_DESTROY(_inp) \
  	mtx_destroy(&(_inp)->inp_create_mtx)
  
  
  #ifdef SCTP_LOCK_LOGGING
  #define SCTP_INP_RLOCK(_inp)	do { 					\
  	if(SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOCK_LOGGING_ENABLE) sctp_log_lock(_inp, (struct sctp_tcb *)NULL, SCTP_LOG_LOCK_INP);\
          mtx_lock(&(_inp)->inp_mtx);                                     \
  } while (0)
  
  #define SCTP_INP_WLOCK(_inp)	do { 					\
  	if(SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOCK_LOGGING_ENABLE) sctp_log_lock(_inp, (struct sctp_tcb *)NULL, SCTP_LOG_LOCK_INP);\
          mtx_lock(&(_inp)->inp_mtx);                                     \
  } while (0)
  
  #else
  
  #define SCTP_INP_RLOCK(_inp)	do { 					\
          mtx_lock(&(_inp)->inp_mtx);                                     \
  } while (0)
  
  #define SCTP_INP_WLOCK(_inp)	do { 					\
          mtx_lock(&(_inp)->inp_mtx);                                     \
  } while (0)
  
  #endif
  
  
  #define SCTP_TCB_SEND_LOCK_INIT(_tcb) \
  	mtx_init(&(_tcb)->tcb_send_mtx, "sctp-send-tcb", "tcbs", MTX_DEF | MTX_DUPOK)
  
  #define SCTP_TCB_SEND_LOCK_DESTROY(_tcb) mtx_destroy(&(_tcb)->tcb_send_mtx)
  
  #define SCTP_TCB_SEND_LOCK(_tcb)  do { \
  	mtx_lock(&(_tcb)->tcb_send_mtx); \
  } while (0)
  
  #define SCTP_TCB_SEND_UNLOCK(_tcb) mtx_unlock(&(_tcb)->tcb_send_mtx)
  
  #define SCTP_INP_INCR_REF(_inp) atomic_add_int(&((_inp)->refcount), 1)
  #define SCTP_INP_DECR_REF(_inp) atomic_add_int(&((_inp)->refcount), -1)
  
  
  #ifdef SCTP_LOCK_LOGGING
  #define SCTP_ASOC_CREATE_LOCK(_inp) \
  	do {								\
  	if(SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOCK_LOGGING_ENABLE) sctp_log_lock(_inp, (struct sctp_tcb *)NULL, SCTP_LOG_LOCK_CREATE); \
  		mtx_lock(&(_inp)->inp_create_mtx);			\
  	} while (0)
  #else
  
  #define SCTP_ASOC_CREATE_LOCK(_inp) \
  	do {								\
  		mtx_lock(&(_inp)->inp_create_mtx);			\
  	} while (0)
  #endif
  
  #define SCTP_INP_RUNLOCK(_inp)		mtx_unlock(&(_inp)->inp_mtx)
  #define SCTP_INP_WUNLOCK(_inp)		mtx_unlock(&(_inp)->inp_mtx)
  #define SCTP_ASOC_CREATE_UNLOCK(_inp)	mtx_unlock(&(_inp)->inp_create_mtx)
  
  /*
   * For the majority of things (once we have found the association) we will
   * lock the actual association mutex. This will protect all the assoiciation
   * level queues and streams and such. We will need to lock the socket layer
   * when we stuff data up into the receiving sb_mb. I.e. we will need to do an
   * extra SOCKBUF_LOCK(&so->so_rcv) even though the association is locked.
   */
  
  #define SCTP_TCB_LOCK_INIT(_tcb) \
  	mtx_init(&(_tcb)->tcb_mtx, "sctp-tcb", "tcb", MTX_DEF | MTX_DUPOK)
  
  #define SCTP_TCB_LOCK_DESTROY(_tcb)	mtx_destroy(&(_tcb)->tcb_mtx)
  
  #ifdef SCTP_LOCK_LOGGING
  #define SCTP_TCB_LOCK(_tcb)  do {					\
  	if(SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOCK_LOGGING_ENABLE)  sctp_log_lock(_tcb->sctp_ep, _tcb, SCTP_LOG_LOCK_TCB);          \
  	mtx_lock(&(_tcb)->tcb_mtx);                                     \
  } while (0)
  
  #else
  #define SCTP_TCB_LOCK(_tcb)  do {					\
  	mtx_lock(&(_tcb)->tcb_mtx);                                     \
  } while (0)
  
  #endif
  
  
  #define SCTP_TCB_TRYLOCK(_tcb) 	mtx_trylock(&(_tcb)->tcb_mtx)
  
  #define SCTP_TCB_UNLOCK(_tcb)		mtx_unlock(&(_tcb)->tcb_mtx)
  
  #define SCTP_TCB_UNLOCK_IFOWNED(_tcb)	      do { \
                                                  if (mtx_owned(&(_tcb)->tcb_mtx)) \
                                                       mtx_unlock(&(_tcb)->tcb_mtx); \
                                                } while (0)
  
  
  
  #ifdef INVARIANTS
  #define SCTP_TCB_LOCK_ASSERT(_tcb) do { \
                              if (mtx_owned(&(_tcb)->tcb_mtx) == 0) \
                                  panic("Don't own TCB lock"); \
                              } while (0)
  #else
  #define SCTP_TCB_LOCK_ASSERT(_tcb)
  #endif
  
  #define SCTP_ITERATOR_LOCK_INIT() \
          mtx_init(&sctp_it_ctl.it_mtx, "sctp-it", "iterator", MTX_DEF)
  
  #ifdef INVARIANTS
  #define SCTP_ITERATOR_LOCK() \
  	do {								\
  		if (mtx_owned(&sctp_it_ctl.it_mtx))			\
  			panic("Iterator Lock");				\
  		mtx_lock(&sctp_it_ctl.it_mtx);				\
  	} while (0)
  #else
  #define SCTP_ITERATOR_LOCK() \
  	do {								\
  		mtx_lock(&sctp_it_ctl.it_mtx);				\
  	} while (0)
  
  #endif
  
  #define SCTP_ITERATOR_UNLOCK()	        mtx_unlock(&sctp_it_ctl.it_mtx)
  #define SCTP_ITERATOR_LOCK_DESTROY()	mtx_destroy(&sctp_it_ctl.it_mtx)
  
  
  #define SCTP_WQ_ADDR_INIT() do { \
          mtx_init(&SCTP_BASE_INFO(wq_addr_mtx), "sctp-addr-wq","sctp_addr_wq",MTX_DEF); \
   } while (0)
  
  #define SCTP_WQ_ADDR_DESTROY() do  { \
          if(mtx_owned(&SCTP_BASE_INFO(wq_addr_mtx))) { \
               mtx_unlock(&SCTP_BASE_INFO(wq_addr_mtx)); \
          } \
  	    mtx_destroy(&SCTP_BASE_INFO(wq_addr_mtx)); \
        }  while (0)
  
  #define SCTP_WQ_ADDR_LOCK()	do { \
               mtx_lock(&SCTP_BASE_INFO(wq_addr_mtx));  \
  } while (0)
  #define SCTP_WQ_ADDR_UNLOCK() do { \
  		mtx_unlock(&SCTP_BASE_INFO(wq_addr_mtx)); \
  } while (0)
  
  
  
  #define SCTP_INCR_EP_COUNT() \
                  do { \
  		       atomic_add_int(&SCTP_BASE_INFO(ipi_count_ep), 1); \
  	        } while (0)
  
  #define SCTP_DECR_EP_COUNT() \
                  do { \
  		       atomic_subtract_int(&SCTP_BASE_INFO(ipi_count_ep), 1); \
  	        } while (0)
  
  #define SCTP_INCR_ASOC_COUNT() \
                  do { \
  	               atomic_add_int(&SCTP_BASE_INFO(ipi_count_asoc), 1); \
  	        } while (0)
  
  #define SCTP_DECR_ASOC_COUNT() \
                  do { \
  	               atomic_subtract_int(&SCTP_BASE_INFO(ipi_count_asoc), 1); \
  	        } while (0)
  
  #define SCTP_INCR_LADDR_COUNT() \
                  do { \
  	               atomic_add_int(&SCTP_BASE_INFO(ipi_count_laddr), 1); \
  	        } while (0)
  
  #define SCTP_DECR_LADDR_COUNT() \
                  do { \
  	               atomic_subtract_int(&SCTP_BASE_INFO(ipi_count_laddr), 1); \
  	        } while (0)
  
  #define SCTP_INCR_RADDR_COUNT() \
                  do { \
   	               atomic_add_int(&SCTP_BASE_INFO(ipi_count_raddr), 1); \
  	        } while (0)
  
  #define SCTP_DECR_RADDR_COUNT() \
                  do { \
   	               atomic_subtract_int(&SCTP_BASE_INFO(ipi_count_raddr),1); \
  	        } while (0)
  
  #define SCTP_INCR_CHK_COUNT() \
                  do { \
    	               atomic_add_int(&SCTP_BASE_INFO(ipi_count_chunk), 1); \
  	        } while (0)
  #ifdef INVARIANTS
  #define SCTP_DECR_CHK_COUNT() \
                  do { \
                         if(SCTP_BASE_INFO(ipi_count_chunk) == 0) \
                               panic("chunk count to 0?");    \
    	               atomic_subtract_int(&SCTP_BASE_INFO(ipi_count_chunk), 1); \
  	        } while (0)
  #else
  #define SCTP_DECR_CHK_COUNT() \
                  do { \
                         if(SCTP_BASE_INFO(ipi_count_chunk) != 0) \
    	               atomic_subtract_int(&SCTP_BASE_INFO(ipi_count_chunk), 1); \
  	        } while (0)
  #endif
  #define SCTP_INCR_READQ_COUNT() \
                  do { \
  		       atomic_add_int(&SCTP_BASE_INFO(ipi_count_readq),1); \
  	        } while (0)
  
  #define SCTP_DECR_READQ_COUNT() \
                  do { \
  		       atomic_subtract_int(&SCTP_BASE_INFO(ipi_count_readq), 1); \
  	        } while (0)
  
  #define SCTP_INCR_STRMOQ_COUNT() \
                  do { \
  		       atomic_add_int(&SCTP_BASE_INFO(ipi_count_strmoq), 1); \
  	        } while (0)
  
  #define SCTP_DECR_STRMOQ_COUNT() \
                  do { \
  		       atomic_subtract_int(&SCTP_BASE_INFO(ipi_count_strmoq), 1); \
  	        } while (0)
  
  
  #if defined(SCTP_SO_LOCK_TESTING)
  #define SCTP_INP_SO(sctpinp)	(sctpinp)->ip_inp.inp.inp_socket
  #define SCTP_SOCKET_LOCK(so, refcnt)
  #define SCTP_SOCKET_UNLOCK(so, refcnt)
  #endif
  
  #endif
  